It is at times of interest to place electric power equipment at inaccessible locations or hostile environments such as on the sea bed, in a well, a mine, a cave or a pit, for instance for providing power for other equipment used in oil and gas production.
In this case electric or electronic equipment, such as transformers, frequency converters, switchgears etc. may be placed in one or more enclosures in the hostile environment.
The equipment does sometimes need to be controlled in order to perform a required functionality, such as in order to deliver electric power of a distribution system. This type of control is often termed process control. Sensor signals are then collected from the inaccessibly located equipment and used for control purposes.
US 2014/0035504 does for instance describe the collection of signals subsea and transmitted to a topside controller via a fiber-optic link for process control.
Also protection functions and/or protection devices may need to be installed. It may for instance be needed a protection device for swift disconnection of loads connected to a power equipment such as a switchgear.
Local protection of subsea equipment has been known to have been used in relation to Wave Power Generation.
In order to be able to perform a protective function the protection device will then act on sensor measurements obtained in the equipment.
The sensor signals do then sometimes need to be of good quality in order for the protection function to be able to handle them properly. This may especially be a problem if the environment is noisy.
Such signals may have a wide range and low level sensor signal are therefore sensible to noise.
Furthermore, maintenance is typically also a problem at inaccessible locations. It may for instance be virtually impossible to perform repair at an inaccessible site. Maintenance would then typically require the replacement of whole modules. There may therefore also be a need for a protective arrangement that simplifies replacement of parts of it.
There is thus room for improvement in relation to protection of subsea equipment.